In vitro comparison of the diffusion from two new multi-hole wound catheters: a preliminary study

ABSTRACT

Background: There are no st and ard wound catheters to provide constant diffusion to give effective infiltration of local anesthetics. We developed two new catheters and compared the diffusion from these two catheters as a preliminary study. Methodology: The catheter-A was divided into four equal lumens inside. It has four holes of 0.1 mm in diameter, one hole in each lumen with an interval of 20 mm and 90 degrees angle starting at 10 mm from the tip of the catheter. The catheter-B is a single-lumen catheter that has a first hole of 0.3 mm in diameter at 10 mm from the tip and has another 9 holes of 0.1 mm in diameter with an interval of 10 mm and 180 degrees angle starting at 10 mm from the first hole. Both had 1 mm external diameter. Each catheter was put on the test tubes. A dye was infused at a rate of 2, 4, or 10 ml/h. Results: The catheter-A had almost homogenous diffusion from all holes at all flow rates, but the catheter-B had uneven diffusion. Conclusions: A four-lumen catheter might be better than a single lumen catheter to provide more homogenousdiffusion. Key words wound infiltration, catheter, postoperative analgesia